Speaking at the London Chest Hospital in Bethnal Green, east London, doctors told of the nerve-racking 80 minutes in which Fabrice Muamba's heart failed to beat.

The cardiologist who leapt from his seat in the crowd and rushed on to the pitch to help the Bolton footballer after he suffered a cardiac arrest during an FA Cup match said Fabrice Muamba was already making jokes again while in intensive care.

Dr Andrew Deaner recalled his visit to Muamba after he had just woken up. "I whispered into his ear 'What's your name?'," he said, and the footballer gave his name.

Dr Deaner went on: "I said 'I understand you're a very good footballer'. And he said 'I try'."

The doctor, who has been widely praised for his efforts to save the 23-year-old footballer, added: "If you're going to use the term miraculous, it could be used here."

Meanwhile Bolton Wanderers' team doctor Jonathan Tobin, who also rushed to the player's side when he collapsed on Saturday, admitted breaking down in tears afterwards, fearing the worst.

"It was 48 minutes from the time he collapsed to the time he reached the hospital and then it was a further 30 minutes in the hospital they were working on him without his heart having a muscular beat," he said.

"(Eighty minutes) without his heart beating and without him breathing - in effect he was dead in that time."

He added: "He's made a remarkable recovery so far. We don't want to get ahead of ourselves...

"As things stand, I think his life is not in danger at this time. His neurological function is looking very good but it is early days."

Describing a visit to Congo-born player yesterday, he said: "I went in and he said 'Hi, doc.' "I asked him how he was and he said 'Fine'."

Muamba, who collapsed during his team's clash with Tottenham, had asked him what had happened.

"I explained to him what had happened," Dr Tobin said. "That's the sort of level of communication I have had with Fabrice."

Muamba's level of recovery after the long time he had spent with no heart beat was "very unusual", he said.

He added: "But it's very unusual to look after a very fit 23-year-old who's been playing football for 40 minutes before he collapsed and I think that may have had something to do with it."

The medics were unable to confirm whether Muamba would ever be able to resume playing professional football however.

"These are the very first steps of a very long pathway that Fabrice is going to go down," Dr Tobin said.

Consultant cardiologist Dr Sam Mohiddin, who has been caring for Muamba at the hospital, said it was "extraordinary" for someone whose heart has stopped beating for as long as the player's did to make the kind of progress he has made.

"Fabrice has continued to demonstrate positive signs of recovery and he has not only exceeded our expectations but also our hopes in the way he's recovered," he said.

"But this remains very early in what could be a lengthy recovery period."

Dr Mohiddin said it was "far too early to say" what caused Muamba's heart to stop as Bolton played Tottenham in the FA Cup match at White Hart Lane in north London and could not predict how long it might be before Muamba is fully recovered.

The consultant, who is monitoring Muamba's progress in intensive care, said a full recovery was a possibility but remained hesitant on whether the footballer could return to play for his club.

"I don't think we can even begin to discuss that," he said.

Insisting there remained many "unknowns," he added: "It's a testament to his progress that we can even think of asking that question now.

"We still have to talk about a spectrum of possible outcomes. At one end of that spectrum is a normal life."

The player was given a routine screening for heart defects in August and was checked again on Sunday, with the test producing a "normal" result, medics said.

Dr Mohiddin said such procedures were not perfect.

The player could eventually be fitted with a pacemaker-type device, implanted under the skin, to act as a safety net in the event of another cardiac arrest.

"Almost everyone who comes into us with a cardiac arrest, who has been resuscitated, will be considered for a defibrillator because they are life-saving devices," Dr Mohiddin said.

"Essentially you are making an assessment that what's happening may happen again.

"If there's any risk that's the case, we want a safety net. That's what the defibrillator provides."

Muamba's family were said to be bearing up while he continued his recovery.

Dr Tobin said: "His family are fine. His father and fiancee have been unbelievably strong throughout this...They've been incredible."

But the Tottenham players, who stopped their game after Muamba's sudden collapse, were "very upset" and were being offered extra cardiac screening and counselling.

Dr Mughal said: "The players obviously witnessed a very traumatic event...so we took measures to try and help them overcome the events and one of those measures was bringing forward an offer of cardiac screening to them."